It's an icon of a hand holding three fingers up. The three fingers being held up are the index finger, middle finger and ring finger. It appears to be a right hand that would show the back of the hand facing towards you.

Three Fingers and other 89,000 icons from Icons8 icon pack follow the visual guidelines of the operating systems: Windows, iOS, Android KitKat, and Material. PNG format is free up to 100x100 px.

Idea of Three Fingers Icon by Anonymous

We've received the idea on February 25, 2012 and created the icons on April 10, 2012

Touch-related icons demonstrating things like pinch-to-zoom, multi-touch, etc.
Hand with index finger extended
Whole hand
Hand with two fingers extended
Hand with finger and thumb
Two hands, each with a finger extended